thanks bart - I was able to determine that it is not working for format ids 43, 168 and 169 - and yes, I do recognize, that if 't1' does not resolve to a value in the data, regex extraction would fail - my question was mostly - why doesnt this seemingly correct regex -

When putting a smiley right before a closing parenthesis, do you:

Use two parentheses: (Like this: :) )
Use one parenthesis: (Like this: :)
Reverse direction of the smiley: (Like this: (: )
Use angle/square brackets instead of parentheses
Use C-style commenting to set the smiley off from the closing parenthesis
Make the smiley a dunce: (:>
I disapprove of emoticons
Other